What are autism spectrum disorders? How many people are affected?
Hallmayer: Children with autism find it difficult to relate to others. They have problems with language and social interactions, and many exhibit significant mental impairment. Those with Asperger’s disorder have similar social difficulties but they achieve normal language milestones. A third category, known as “pervasive developmental disorders – not otherwise specified,” is used for children who don’t have all the symptoms of autism or Asperger’s, but who still struggle in these areas. On Feb. 9, the Centers for Disease Control released a 14-state study that suggested the incidence of autism spectrum disorders could be as high as one in 150 children. Q: Are autistic spectrum disorders genetic? If so, why do they vary in severity? Hallmayer: Autism is strongly genetic. If one identical twin individual is affected the chance that the co-twin is also affected is between about 70 and 90 percent vs. about 3 to 5 percent in the case of a non-identical twin. However, this does not mean that
